Nicole Kidman,Ashley Tisdale, Emma Stone and Camilla Belle all tried the trend this week. See their looks, vote on who you think wore the trend best and learn when to wear it and when to avoid it!

When to wear the trend:

Nicole wore red lipstick and a red dress to a film screening July 13 and she followed my top three tips for wearing red-on-red exactly! Read them here.

Ashley looks luminous in a creamy colored dress with a creamy lip color topped with a gloss at a July 19 Miu Miu fashion event. The light lip color works well with her tan skin.

Camilla, at the same event, wore a rose petal pink lipstick that brought out the pink flowers on her dress perfectly. Using a lip color is a great way to highlight a pretty accent in your outfit!

Emma wore a pink and red dress with pink lipstick. If you are going to match your lip color to your outfit, make sure you match the shade exactly, otherwise you’re adding an entirely new color palette to the look.

When to avoid the trend:

1. When you’re wearing a very dark color. Dark clothes with dark lipstick is a very harsh look and can be incredibly hard to pull off.

2. When the color you’re wearing in your outfit would not look good on your lips. Orange dress? Don’t go for orange lipstick. It’s just too much.

3. When your outfit has a wild pattern. Notice that all four celebs sporting the trend all have very simple dresses on. A fun pattern is enough of a statement — you don’t need to add another element into that look.